The bash shell is an omnipresent command-line interpreter used by default in Unix and Linux, and by extension, Apple’s OS X software. The shell itself is decades old, and it turns out the bug has been present for the last 22 years without detection.

Linux stewardship company Red Hat released a series of fixes to patch up the eight or so versions of bash that were vulnerable. On Friday, Red Hat released a second round of patches to resolve newly discovered security flaws, and those discoveries keep coming.

Shellshock exploits are spiking with the development of “wopbot,” the first botnet designed specifically to target the bash bug.

At the moment, the only people who need to worry about patching the Shellshock bug right away are system administrators and people who have tweaked the advanced Unix settings on machines running OS X or Linux.